Question

Q 11 

Answer 1

we have,

C.I	f	class mark        x	fx
0 - 10	8	5	40
10 - 20	5	15	75
20 - 30	12	25	300
30 - 40	35	35	1225
40 - 50	45	45	1080
50 - 60	55	55	880
	∑ f = 100		∑ fx =  3600

Now , Mean = `(∑fx)/(∑f) = 3600/100 = 36`